Sounds like a perfect way to lose a lot of business to me.
Not to me. As another poster notes above, corporates are willing victims. To go open source sounds risky, complex, dangerous, particularly if you're a corporate suit. There would be voices saying "don't build your own systems, you aren't clever enough, it isn't a core competence, buy software from somebody like SAP or Oracle who know what's what". And whenever some "expert" is consulted from the likes of BCG, McKinsey, PWC et al, they'll be falling over themselves to recommend a single ERP architecture from the big boys (sprinkled with the obligatory references to cloud, machine learning, best shoring, digital best practice, etc).
SAP (and others) have their foolish customers by the short and curlies. All the customers can do is pay up. Even if they wanted to build their own, a complex ERP, or even the CRM module would at fastest be five years from inception to live operation, probably more like seven years, and very few companies have that sort of patience.