Great question — answering as the UphillTech team:
It will/does NOT have a negative impact on your domain. Simple is that. It may even have a positive impact on your main page, provided the child pages were up to standard and of value and received backlinks. If not, they may not provide any advantage, but simultaneously will not hurt your SEO effort.
Full answer by Georg Keferböck: https://webmasters.stackexchange.com/a/124108 (CC BY-SA 4.0).
Need it done for your business? UphillTech.