I completely agree with you on (at least in terms of Twilio's experience):
> would Optimizely be doing much better if they hadn't pivoted into enterprise hell? Or would they be a much smaller company?
We were definitely going to hit a ceiling if we didn't add enterprise features and work on getting all the various certifications that large companies will require to even start talking to you, and build a sales force that knew how to sell to larger companies. If we hadn't done all that, we'd be a much smaller company today, and likely a competitor would have done it instead and eaten our lunch.