That sounds much more like corporate interests and a related lack of will to get embroiled in moderation than evidence of ideological preference.

The t_d folks liked to go to Reddit to organise their nazi rallies and that basically just meant more traffic for Reddit which on a crude level is generally good from Reddit's perspective. It can be bad when it scares advertisers or when it drives away a larger amount of traffic from people put off by an apparently Nazi bent to the website they came to for killing time, compared to what they gained from a small group of freaks.

It's one subcommunity of a very large forum website that from afar just looks like another, additional contingent of users. If they start to hear some grumblings about it being a bit fucked up to allow this kind of community they could be tempted to intervene but that would mean taking active moderation steps which companies like Reddit have mostly not seen as their job or priority, especially Reddit which gets other people to do it for them for free, and then on top of that there's some degree of risk that doing so would damage the brand when it causes a stink and people start screaming censorship.

Eventually it becomes worth acting to get rid of something like this when enough stink is raised that news of the existence of the community and the types of discussions going on there goes mainstream and starts to spook advertisers and an actually large number of mainstream users.

This to me looks far more like a deeply held and passionate belief in the idea of "more money, and not less money" than for Nazism. I'm sure they'd just as soon embrace Nazism if the winds shifted and they thought on balance it'd work out more profitable to keep the right wing extremists happy than the rest of society, but at least right now it's pretty much not the case so they're forced to act despite a cynical reluctance wholly unrelated to ethos.