It's well-known and indeed massively controversial[1] that there's a CrunchFund/TechCrunch conflict. Arrington left TechCrunch because of his desire to return to investing about a year ago[2], after the short stint at doing both journalism and investing in parallel. According to CrunchBase, this was coincidentally the same month that CrunchFund invested in Orchestra[3]. Both he and MG returned in October 2012[4], but both have hardly written any TC pieces since then. Why? Probably because they're quite busy with their day jobs running CrunchFund.
Additionally, on many posts with CrunchFund conflicts, they have been called out at the end of each article (see http://techcrunch.com/2011/06/30/andreessen-horowitz-adds-je...). They probably have been a bit lax about that as of late since the CrunchFund guys aren't really involved in TC (compared with the often torrential output of most other staff writers).
TechCrunch coverage did probably get Mailbox some users, and CrunchFund as a VC probably did add some value to their company, but the effects and importance of TechCrunch itself are wildly overstated. Probably more important is that the Mailbox/Orchestra team is top notch at making incredible mobile products (Orchestra won one of Apple's Top App award in 2011 http://blog.orchestra.com/orchestra-is-productivity-app-of-2...), had hundreds of thousands of active users within a very short amount of time (with only a tiny insignificant fraction of those coming from TC), and Dropbox can probably provide a better home for a lot of the Really Hard problems with email at that kind of scale.
Like I get why OP seems alarmed, but it's pretty naive to think that TechCrunch matters in any important way to the success or financial outcome of a company. Just read about the "TechCrunch pop"[5]; their users rarely not stay with or give lasting value to a product. If you want to belittle the astounding accomplishments of the Mailbox team, at least don't pick something like TechCrunch to do it over.
[1]: http://www.nytimes.com/2011/09/02/technology/michael-arringt...
[2]: http://www.adweek.com/news/technology/michael-arrington-leav...
[3]: http://www.crunchbase.com/company/orchestra
[4]: http://techcrunch.com/2012/10/23/getting-the-band-back-toget...
[5]: http://viniciusvacanti.com/2012/11/19/the-depressing-day-aft...