Don't know about Rob Pike in particular but Ken Thompson, who probably had the same reasons for "hating" Stroustrup, had this to say about him (from Coders at Work):
Seibel: You were at AT&T with Bjarne Stroustrup. Were you involved at all in the development of C++?
Thompson: I'm gonna get in trouble.
Seibel: That's fine.
Thompson: I would try out the language as it was being developed and make comments on it. It was part of the work atmosphere there. And you'd write something and then the next day it wouldn't work because the language changed. It was very unstable for a very long period of time. At some point I said, no, no more.
In an interview I said exactly that, that I didn't use it just because it wouldn't stay still for two days in a row. When Stroustrup read the interview he came screaming into my room about how I was undermining him and what I said mattered and I said it was a bad language. I never said it was a bad language. On and on and on. Since then I kind of avoid that kind of stuff.
Seibel: Can you say now whether you think it's a good or bad language?
Thompson: It certainly has its good points. But by and large I think it's a bad language. It does a lot of things half well and it's just a garbage heap of ideas that are mutually exclusive. Everybody I know, whether it's personal or corporate, selects a subset and these subsets are different. So it's not a good language to transport an algorithm—to say, “I wrote it; here, take it.” It's way too big, way too complex. And it's obviously built by a committee.
Stroustrup campaigned for years and years and years, way beyond any sort of technical contributions he made to the language, to get it adopted and used. And he sort of ran all the standards committees with a whip and a chair. And he said “no” to no one. He put every feature in that language that ever existed. It wasn't cleanly designed—it was just the union of everything that came along. And I think it suffered drastically from that.
Seibel: Do you think that was just because he likes all ideas or was it a way to get the language adopted, by giving everyone what they wanted?
Thompson: I think it's more the latter than the former.
Interesting opinion, it certainly shows the broad mindset behind Golang (and its predecessors Alef and Limbo). Also let's face it, it really took Cyclone and Rust to prove that a broadly C++ish language could be made both safe for large-scale systems and developer-friendly. If your only point of reference is C++ itself, these remarks are not wrong per se.
Seibel: You were at AT&T with Bjarne Stroustrup. Were you involved at all in the development of C++?
Thompson: I'm gonna get in trouble.
Seibel: That's fine.
Thompson: I would try out the language as it was being developed and make comments on it. It was part of the work atmosphere there. And you'd write something and then the next day it wouldn't work because the language changed. It was very unstable for a very long period of time. At some point I said, no, no more.
In an interview I said exactly that, that I didn't use it just because it wouldn't stay still for two days in a row. When Stroustrup read the interview he came screaming into my room about how I was undermining him and what I said mattered and I said it was a bad language. I never said it was a bad language. On and on and on. Since then I kind of avoid that kind of stuff.
Seibel: Can you say now whether you think it's a good or bad language?
Thompson: It certainly has its good points. But by and large I think it's a bad language. It does a lot of things half well and it's just a garbage heap of ideas that are mutually exclusive. Everybody I know, whether it's personal or corporate, selects a subset and these subsets are different. So it's not a good language to transport an algorithm—to say, “I wrote it; here, take it.” It's way too big, way too complex. And it's obviously built by a committee.
Stroustrup campaigned for years and years and years, way beyond any sort of technical contributions he made to the language, to get it adopted and used. And he sort of ran all the standards committees with a whip and a chair. And he said “no” to no one. He put every feature in that language that ever existed. It wasn't cleanly designed—it was just the union of everything that came along. And I think it suffered drastically from that.
Seibel: Do you think that was just because he likes all ideas or was it a way to get the language adopted, by giving everyone what they wanted?
Thompson: I think it's more the latter than the former.