The wayfinding signs are clear enough: "coast via Wallsend" and "coast via South Gosforth." From the entrance hall its one escalator for one set of platforms and one escalator for the other, and at platform level there's a staircase between the two.
Someone who can't follow those signs probably shouldn't be out unsupervised on a public transport network.
The only issue I have with Monument (and it's not restricted to Monument, Central Station is just as bad) is how much of a pain in the backside the step-free access is. It's one lift from street level to the entrance hall and then another one to platform level. One lift serving both sets of platforms really isn't sufficient anymore either, but changing that will cost mega money.
If the wayfinding were good, people wouldn't be asking quite as much as they do, this much is hard to deny design-wise. I've travelled to many networks over the years and still I feel if I was new to Newcastle, Monument would confuse me and it did as a kid. Friends of mine from other regions have outright said things like"wow there's a lot of signs here, what is Heworth?". It's also important to note that not all travellers will be accessing the concourse which equally could have larger and clearer signs - some will be using Monument purely to interchange lines.
The signage just is not very visible or contrasting, it all blends together and it's overly wordy with very little in the way of typographical hierarchy. Finding the way out can be hard because the Exit signs are not highlighted differently from any other exit signs. TfL for example, highlight the Way Out in black.
Nexus don't acknowledge the green line as... A green line so there's no simple or visual way for the signage to say "go downstairs for green line" other than "trains to heworth and south hylton". People are less likely to know the exact termini of each line and cross-referencing it with the map isn't necessarily easy to do given we have 60 stations which is why I think Monument's wayfinding system is flawed.
Why can't the station refer to platform 3 and 4 as east and west from monument and 1 and 2 as north and south through the signage? I would say people generally know what direction they're looking to go in and if not, the clearest signage Monument has is the platform-based line maps - these are helpful when identifying your platform and are effective in other regions such as London too.
My two cents as a graphic designer is it's not a fair assumption to argue that everyone is incompetent, "who cares, if you can't read it, you shouldn't travel unsupervised" without assessing the signage as a potential issue.