Maybe things have changed but the VC model is usually unicorn or GTFO. Of course not every company will turn into one but every company they invest in should have the potential. If I'm a VC I invest in Arduino because of two storylines. It's either the "Coke" of microcontrollers (sticky brand) or the "Github of microcontrolers" (sticky platform via IDE) or a combination of both.
VC as an asset class encompasses a lot of different risk/reward profiles
What you're describing is more typical of a seed fund that is counting on one deal to return the portfolio
In a growth deal like this, esp with such an old company by VC terms, funds tolerate lower upside in exchange for capped downside and predictable returns, given that the chances the chances of complete failure/bankruptcy are comparatively less
