A company might decide to allocate more resources towards marketing and product design over recruitment because its more convenient. Recruitment implies the need to find new staff and new hires, rather than just funneling resources to staff that are already under your employment. Further recruiting effectively can actually cost a decent chunk, so the easier solution for a large company would be to put the resources towards the existing department. Finding good matches for a department is itself already particularly challenging, but that doesn’t take in account negotiating with these potential employees to get them hired. Now this not be the case for a smaller company with less employees as they probably care far more about hiring people who fit into the role they are hiring for. However I would argue that a large corporation is more looking for someone to fill a role with given responsibilities and tasks.
Starting with weaknesses of not focusing resources towards employee recruitment and selection, the biggest issue is inefficiency. If you have people who do not necessarily fit into the role in your team as well as they could be then it will lead towards inefficiency. On the other side of this if you hire someone who you know will fit well into your team and has the skills to compliment it, they will likely be far more efficient. The strength in spending time and resources on good recruitment is you will not have to spend more resources down the line picking up slack.