The phrase "gratuitous use" means using something unnecessarily or excessively, without any genuine reason or purpose. It suggests that whatever is being done or included is excessive and lacks justification. Full definition
iFixit gave B&N's gadget a repairability score of six out of ten (Kindle Fire got an eight), because of gratuitous use of adhesives and a battery that requires removal of the motherboard to be extracted. (theverge.com)
Bonus points for gratuitous use of suspenders and bow ties. (edutopia.org)
The Kyocera Hydro Vibe is a small and thick, by today's standards, with gratuitous use of hard plastic and a few different textures and finishes that try to make it look fancy but generally make it seem cheap. (androidcentral.com)